Today programme presenter Humphrys, 74, faced a growing backlash over remarks that he made in a private conversation with North America editor Jon Sopel. But there were also concerns over how the comments were made public. One BBC insider said: “Because of the open mic it can be heard in other studios so someone is spying on the Today programme.”

Mr Humphrys came under fire from MPs and some colleagues over his remarks in the wake of BBC China editor Carrie Gracie quitting her post over pay inequality. She was co-presenting Today this week and a transcript of an alleged conversation between Humphrys and Sopel, ahead of a scheduled interview, was leaked.

Humphrys says: “Slight change of subject, the first question will be how much of your salary you are prepared to hand over to Carrie Gracie to keep her, and then a few comments about your other colleagues, you know, like our Middle East editor [Jeremy Bowen] and the other men who are earning too much.” Sopel replies: “I mean, obviously if we are talking about the scope for the greatest redistribution I’ll have to come back and say well yes Mr Humphrys, but…”

Carrie Gracie, who has resigned from the BBC as China editor (PA)

Humphrys continues: “And I could save you the trouble as I could volunteer that I’ve handed over already more than you f***ing earn but I’m still left with more than anybody else and that seems to me to be entirely just — something like that would do it?”

Sopel, 58, who seems to be reluctant to be drawn into the conversation, says: “Don’t …” However, his questioner carries on: “Oh dear God. She’s actually suggested that you should lose money — you know that don’t you?”

BBC Woman’s Hour presenter Jane Garvey condemned the remarks. “The #Humphrys — Sopel exchange reveals, very neatly, what we’re up against. And a useful reminder to be ever careful in a room with microphones. #bbcwomen,” she tweeted.

Former BBC journalist Miriam O’Reilly, who won a tribunal case against the corporation in 2011, claimed to have heard the recording and tweeted that it was “base and beneath what the public would expect to hear from John Humphrys. Winifred Robinson was stood down for tweeting support for @BBCCarrie I expect the same will now happen with Mr Humphrys.”

Robinson, presenter for Radio 4 show You and Yours, was taken off air this week after posting her views on equal pay. The show’s focus on Tuesday was gender pay and the BBC said it replaced her due to impartiality issues.

O’Reilly described the exchange as “smug and condescending”.

Jess Phillips, who chairs the Women’s Parliamentary Labour Party, said: “Wo-men who speak up are used to being laughed at. Let’s tip the power as well as the money so Humphrys is now the one who is one worried that he spoke up and how it affects his career.”

However, Humphrys insisted his comments had “nothing to do” with Gracie’s campaign. “This was what I thought was an exchange between two old friends who have known each other for 30 years and were taking the mickey out of each other,” he said.

A BBC spokeswoman said: “This was an ill-advised off-air conversation which the presenter regrets. The BBC is committed to getting its pay structures right and we are conducting a comprehensive analysis of presenter pay.”

Gracie quit her China post accusing the corporation of a “secretive and illegal pay culture” after it was revealed two thirds of its stars earning more than £150,000 were male.@nicholascecil